Terry Given wrote:
Kevin Aylward wrote:

In summary, there are differing concepts of what linearity is being
understood to mean in the real world.


No again. Those who are confused about it, and can't admit they are
simply wrong about what amounts to a widely accepted definitional
matter
[snip]
You nor anyone else need take my word for it: it is in *all* the
Signals, Systems, and Communications texts I've ever opened up --
they are wholly consistant with each other; check for yourself. Your
"definition" is not in any of them (af(t) = f(at)???). So I feel
justified in simply saying you are flatly wrong. If you could at
least post a citation from a text that has your definition and a
worked mathematical problem/solution (no "Circuits" junk), then at
least we could say it was all a grand misunderstanding.

herewith a self-confessed doesnt-know-it-all's analysis:
IF
y(x) = mx+c (even KA cant argue with the linearity (and
time-invariance) of this....LOL)
THEN
y(ax) = max+c
AND
ay(x) = max+ac

Look, you picking up on a triviality that was thrown in as a side line
and as as immediate response to a justification of my claims. My claims
stand as correct. I clearly stated what was I consider an appropriate
definition of linearity, i.e. no frequencies present in the output, not
present at the input.

Elementary Sesame-Street Theory (one of these things is not like the
other) clearly shows this "definition" of linearity to be rubbish.

This was, to all intents and purposes, a typo. I was meaning to refer to
a simple constant gain transfer function. Is it really credible, given
that you are obviously aware of my GR papers, that I am to stupid to
know standard definition of linearity.

However, it would seem that you are another one of those sad people who
think

y=x^2

is a linear equation between x and y.


gwhite most certainly has it correct. KA does not.


Dream on. This is bloody absurd.

www.google.com "nonlinear differential equations" 22,000 hits.

You need to get to grips with than fact that the term "linear" is being
used with two different meanings, where *both* meanings are perfectly
valid in their own contexts. Look, I know what gwite white means, its
trivial. It is also trivial to understand that it is not applicable to
analogue design of amplifies.

Next you'll be declaring that "homogeneous" only, means the one specific
definition as used in differential equations. Or how about "canonical"


as a slight aside, I have read H&H about 8 times, and will continue
to do so - it is one of the more useful books on electronics I have
ever bought (and I have about 600 of them). If you do not have that
book - GO AND BUY IT!! I even met WINFIELD Hill at an MIT junkfest
once a few years ago, and had an interesting discussion with him
about my work on high-speed PMSM energy storage flywheels and giant
SMPS. That guy is really smart - I suggest anyone reading this forum
should pay close attention to win's postings (i sure do). As far as
being an "academic" - well, go read H&H - its beauty lies in its
practicality, unlike most texts. Just because someone works in
academia, doesnt mean they are useless (although to be fair, its
usually not a bad first guess).

I hope you not suggesting that I have any negative opinions of Win
because I claimed that I was not an academic.


Likewise I have met plenty of
blithering idiots out doing "real" engineering (its a good thing -
competent people end up being well paid to fix their screw-ups). The
worst ones tend to work in sales (I presume its because they cant get
real jobs)

Really this entire thread has done little more than allow Kevin
Aylward to appear like a pompous idiot, with a somewhat limited
understanding. A BSc and half-a-dozen MSc courses (one A - wow. I
remember those - they are what you get if you dont do well enough for
an A+) simply makes for a failed MSc. Of all the pomposities, I just
loved this one:

No this one is about gwhite being a pretentious prat trying to impress
everyone with a fancy mathematical definition of linearity that has
little or zero relevance in this context, i.e analogue design of
amplifiers. He has *yet* to show how said class A amplifier, as he
claimed, can form a modulator without relying on the fact that the
transfer function of the transistor is non-linear. He has simple
attempted to obscure the issues by making irrelevant technical points.


In all honesty, there is not much I don't know about general
analogue design, although, obviously, I don't claim to know it all.

It kind of makes one wonder just how KA knows there isnt much he
doesnt know.

why do I post on these newsboards? am I being selfish? I dont think
so.

Not consciously, but inherently, there is no other way, that is not if
you believe in evolution, i.e if you are one of those creationists.


Kevin Aylward

http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.